title: CpxP, a stress-combative member of the Cpx regulon.
abstract: The CpxA/R two-component signal transduction system of Escherichia coli can combat a variety of extracytoplasmic protein-mediated toxicities. The Cpx system performs this function, in part, by increasing the synthesis of the periplasmic protease, DegP. However, other factors are also employed by the Cpx system for this stress-combative function. In an effort to identify these remaining factors, we screened a collection of random lacZ operon fusions for those fusions whose transcription is regulated by CpxA/R. Through this approach, we have identified a new locus, cpxP, whose transcription is stimulated by activation of the Cpx pathway. cpxP specifies a periplasmic protein that can combat the lethal phenotype associated with the synthesis of a toxic envelope protein. In addition, we show that cpxP transcription is strongly induced by alkaline pH in a CpxA-dependent manner and that cpxP and cpx mutant strains display hypersensitivity to growth in alkaline conditions.
authors.affiliation: Department of Molecular Biology, Princeton University, New Jersey 08544, USA.
authors.forename: P N
authors.initials: PN
authors.lastname: Danese
authors.forename: T J
authors.initials: TJ
authors.lastname: Silhavy
mesh_terms: D000468:Alkalies / Q000494:pharmacology; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D006863:Hydrogen-Ion Concentration; D008074:Lipoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010755:Organophosphates / Q000378:metabolism; D019897:Periplasm / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D018085:Regulon; D012641:Selection, Genetic; D017386:Sequence Homology, Amino Acid; D012808:Sigma Factor; D015398:Signal Transduction; D014157:Transcription Factors; D014158:Transcription, Genetic
chemical_list: D000468:Alkalies; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C491730:CpxP protein, E coli; C110674:CpxP protein, bacteria; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; C095021:NlpE protein, E coli; D010755:Organophosphates; D012808:Sigma Factor; D014157:Transcription Factors; C063202:sporulation-specific sigma factors; C085504:CpxR protein, Bacteria; C011632:acetyl phosphate; D011494:Protein Kinases; C490475:CpxA protein, E coli; C092472:CpxA protein, bacteria